Answer
Symptom:
P1788-2/4 HYDRAULIC PRESSURE TEST FAILURE
When Monitored and Set Condition:
P1788-2/4 HYDRAULIC PRESSURE TEST FAILURE
When Monitored: In any forward gear with engine speed above 1000 RPM shortly after
a shift and every minute thereafter.
Set Condition: After a shift into a forward gear, with engine speed > 1000 RPM, the TCM
momentarily turns on element pressure to the clutch ckts that don't have pressure to
identify the correct pressure sw closes. If the pressure sw does not close 2 times the code
sets.
POSSIBLE CAUSES
LOSS OF PRIME P1791 PRESENT
RELATED DTC'S PRESENT
Transmission Fluid LEVEL
INTERMITTENT WIRING AND CONNECTORS
TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT OPEN
2/4 PRESSURE SWITCH SENSE CIRCUIT OPEN
2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
INTERNAL TRANSMISSION
TCM - 2/4 HYDRAULIC PRESSURE
Trouble code P1788 means: Hydraulic Pressure Switch: 2-4
Check on the driverside cylinder head. My engine code is on the head.
When the check engine light comes on it should post a code. Use a code reader to see what the code is and ask again.
yes it can. if the check engine light shuts off by itself then chances are either the trouble code is a soft code. A hard code will keep the check engine light on until the problem is fixed and the check engine light is reset.
and what code does the check engine light say ? go by autozone they will check it for free and get the code.
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You can buy the check engine computer and the book comes with it. I know, I bought one. When your check engine light comes on, you plug it in and check the engine and it will give you the code and you look in the book for that code and it gives you the answer.
The check engine light sets a code for diagnostics and you need a code reader. Most auto parts stores sell code readers and most will check the codes for free.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
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